In the Light of the Sun
by Chromanin
Summary: March, 1943. The Chamber of Secret has been opened, and the students of Hogwarts start to fear for their lives. But the one belonging to Salazar Slytherin might not be the only moster living inside the castle...
1. Prologue

**A\N**: This story is a translation of the one I wrote in Italian (link in my biography). English is not my first language, and I'm really trying not to make mistakes; I apologize in advance for any errors you may find. Feel free to tell me so I can correct them. Well, I don't have much to add; this fanfiction was born just for fun, and I hope you will enjoy it. Reviews are welcolmed.

**Disclaimer:** I don't own anything in the Harry Potter Universe, it all belongs to J.K. Rowling.

* * *

The Library of Hogwarts School of Witchcraft and Wizardry was silent. In the section of History of Magic, one of the furthest from the entrance, the light of the moon was shining above the shelves full of books.

A girl was sitting on the floor, leaning against the enormous window. A Heating Spell had been cast on the glass of the window to ensure that the freezing cold would not bother her while she was reading.

The student who had been watching her for a while knew that the girl had probably arrived in the Library a couple of hours before, and that she had headed without hesitation to that particular section. Then she had surely Conjured the red cushions on which she was sitting now, and she had started to read one of that remarkably large volumes that she seemed so fond of.

He knew all that because he had seen her doing so nearly every evening in the last week.

Maybe, in the last few days, she had been aware of his presence, but apparently didn't pay enough attention to him: after all he was just one of the many students that inhabited the Library at every hour of the day, studying or doing their homework. It seemed that nothing could distract her or make her lose her concentration.

That night, in that moment, the two of them were the only people inside the Library. He was sure of it, just as he had made sure that nobody could disturb the girl by the window. Unfortunately for her, absorbed as she was by her stupid book, she didn't realize that it was well past curfew.

"_Lumos_," he whispered, and slowly moved away from the dark of the shelves that had hidden him. He didn't bother to be quiet. Pretending to have just arrived in the Library, he walked towards the girl, keeping his wand high to light the way. She raised her eyes, apparently annoyed by the sudden nuisance. Bless her, she did not have the slightest idea.

"What do we have here? A bookworm? You are breaking curfew, Miss," he scolded her.

Funny, he didn't even know what her name was. She looked familiar; he probably had seen her walking by the corridors of the castle they both lived in. Only a week before, before she caught his attention, if he had seen her outside Hogwarts he wouldn't have recognized her. She looked young, but she couldn't be more than one or two years younger than him.

Lauren? Bonnie? She looked like a Bonnie. But it didn't make sense trying to guess her name, he thought. It would be a lot easier if he didn't know her name, if she was just a stranger.

In the meantime the girl had seen his shining Slytherin Prefect badge and had gotten up, looking in great discomfort. Apparently she didn't like to break rules, then.

"Oh. I – look," she said, glancing quickly at her watch. "I didn't realize it was so late. I'm sorry. I will get back to the Tower at once."

"Not so fast," he retorted. The girl looked resigned, maybe expecting him to deduct a million points from her House or something. He wasn't about to do _that_.

Gingerly, he aimed his wand against her face.

"_Stupefy_."


	2. The Syndrome

**A\N:** Hello again! Thank you for reading. I remind you that English is not my first language, so let me know if you find mistakes. Reviews are welcolmed.

**Disclaimer:** I don't own anything in the Harry Potter Universe, it all belongs to J.K. Rowling.

* * *

_**From the previous chapter:**_

_In the meantime the girl had seen his shining Slytherin Prefect badge and had gotten up, looking in great discomfort. Apparently she didn't like to break rules, then._

_"Oh. I – look," she said, glancing quickly at her clock. "I didn't realize it was so late. I'm sorry. I will get back to the Tower at once."_

_"Not so fast," he retorted. The girl looked resigned, maybe expecting him to deduct a million points from her House or something. He wasn't about to do that._

_Gingerly, he aimed his wand against her face._

_"Stupefy."_

* * *

The girl woke up shouting. She sat on her bed kicking away the blankets and took her head between her hands, shaking. She touched her hair, resisting the urge to tear it away: the headache was so strong that even the presence of her hair was driving her crazy.

After a few seconds, she heard someone pull aside the curtains of her four-poster bed.

"Katerina?!"

Abigail, one of her roommates, was watching her wide-eyed.

"What's wrong with you?", she continued, as the other hadn't answered.

Katerina tried to show an apologetic smile. Her heart was beating fast.

"It's nothing. Sorry I woke you up," she whispered, moving to place her feet down on the soft blue carpet. For a moment, the world seemed to spin.

"You were yelling," said Abigail, looking a little annoyed. "I thought someone was murdering you… hey, are you ok?" she added, now with a slightly concerned tone.

"I'm fine, it's just a headache. And I think I had a nightmare."

For a moment, her head was again full of red flashes and blood. She couldn't remember what her dream was about, but she had to close her eyes in order to fight off the lingering dread that it still caused.

When she felt ready, she got up, reassured her other two roommates and stepped inside the bathroom. While the light magically readjusted itself according to her needs – _not too bright_ – she looked at her reflection in the mirror. She was very pale, her long brown hair was disheveled and she had dark shadows under her eyes. Her hands were still shaking.

Her dark eyes in the mirror were staring back at herself. Then, slowly, her reflection shook its head.  
"You look terrible," it said. "Go back to sleep."  
Katerina let out a sigh and did as she was told.

* * *

Next morning, the Great Hall was unusually quiet.  
The table of the Professors was completely empty; the students were whispering, while a small group of people was around a crying fourth-year Gryffindor girl.

"What happened to Barbara Hammond?" asked Katerina to Abigail while they were sitting at the Ravenclaw table.

Hayley Watson, the earliest-riser of their roommates, whispered:

"It's her sister. Yesterday night she was found near the entrance of the Hufflepuff Common Room." Hayley hesitated. "She was petrified."

Appalled, Abigail placed her pumpkin juice on the table.

"What, the Syndrome again?"

"Yes."

Katerina didn't speak. She didn't knew the Hammonds very well, but she knew that the youngest was just a second-year. She probably couldn't stand a chance against whatever had hit her.

Hogwarts School of Witchcraft and Wizardry wasn't the most ancient wizarding school in the world, nor the richest or the most appreciated; but its history over nine centuries long was the pride of the English magical tradition. Every non-Muggle British citizen was proud to send their children to the very school where the leading figures of the wizarding world gathered to teach, educate and protect young witches and wizards.

Those who were not blinded by pride, however, knew very well that Hogwarts was certainly not heaven. Only a decade before the school had been hit by a terrible scandal: the Defense Against the Dark Arts teacher was found guilty of using his students as test subjects for his experiments regarding Dark Spells. The professor was immediately fired and shut inside St. Mungo, the key of his cell was metaphorically thrown away and the whole story was partially hushed up.

And now, Katerina thought, the Headmaster of Hogwarts was dealing again with a problem that was potentially catastrophic for the public image of the school.

The first student found petrified had been a fifth-year Gryffindor, one of her classmates. For three weeks his body had been stuck, motionless, in the Infirmary; nobody seemed able to figure out a solution to wake him up from his magical coma. The school staff had tried to keep the news from spreading around, but someone had apparently told someone else that the boy had been hit by a mysterious magical sickness, and after a few days everyone was aware of it.

When the second victim, a third-year Hufflepuff, had been found in a bathroom on the second floor, the situation got out of hand. It was mid-afternoon, and half of the student body was there to watch the poor girl being slowly carried to the Infirmary.

Inside the castle everyone had their personal theory regarding what had happened, but the generally most accepted explanation remained the mysterious sickness. The students started to call it "the Syndrome"; and the victims of the Syndrome were now three.

"Do you think that now some students will decide to go home?", quietly asked Katerina to her Housemates.

"I heard that the Malfoy twins will soon go back to their French mansion," said Barnabas Carter.

"It won't be soon enough," Hayley complained. "Anyway, I surely don't want to go. I am certain that Headmaster Dippet will find a solution. And this year we have our O.W.L.s, we can't go home just like that."

"I really can't wait to see _how_ you will study for your exams when you will be petrified too," said Barnabas sarcastically. Hayley shot him a nasty look.

"According to what his apprentice says, the Erbology Professor might have found a solution. He's trying to use the magical characteristics of the Mandrakes to create a potion that will wake the petrified students," declared Matilda Marchbanks. The topic of the conversation stayed on the characteristics of the Mandrakes until the end of the breakfast. No one of the Professors showed in the Great Hall.

After breakfast, while she was heading to Aritmancy, Katerina made her best to ignore the strange feeling that had tormented her since her awakening from the nightmare. She felt a fastidious prickling on the back of her neck, as if someone was intensely watching her. She turned her head a few times, looking for something that could explain that feeling, but didn't see anything out of the ordinary. When Abigail asked her if she was looking for someone, she just shrugged her shoulders and answered negatively. The other girl didn't ask further.

When the lesson finished, however, she felt that Aritmancy had done nothing to decrease her headache.

"You still have a migraine?", asked Matilda in a sympathetic tone. Katerina, hands covering her forehead and almost laying with her body on the desk, nodded unhappily.

"I do. I think I'll go to the Infirmary to get a painkilling potion. If I am late, will you apologize to Slughorn in my behalf?"

While the girls were nodding, Abigail piped, "I'll go with you. You are as white as a sheet and your eyes are blood-shot: you are frankly scarier than the Bloody Baron, and we don't want to frighten the little kids, do we?"

Katerina stared at her for a moment, speechless. Abigail had her own strange habit to say everything in an extremely serious way, but after five years of knowing each other Katerina understood that it was only a way to hide what she was really thinking, or maybe to mask a peculiar sense of humor. Anyway, she always found quite difficult to determine if the girl was joking or not.

Overlooking the not-so-much flattering comments about her skin and eyes, she thanked her and together they walked towards the Infirmary.

Their way was packed by a thick crowd of second-years, but when they reached their destination they found out that the Infirmary was empty.

"Madam Wainscott?", called Katerina, but the chubby nurse was nowhere to be seen. When she turned to suggest her friend to go back, she realized that she wasn't at her side anymore. She moved her gaze upon the white empty beds, on the tall wardrobes against the walls and at last on the deep end of the room, where Abigail was walking with rapid paces. In front of her there were two dividing curtains. Katerina saw her blonde head pull aside the curtains and carefully peek behind, and then turn again towards her.

"Kat!", called excitedly the girl. "Look!"

Katerina, who was already approaching her, stepped by her side and glanced at what her friend was pointing at.

In front of them there were three parallel beds, disposed one near the other. On the beds lay still three dark figures, completely covered by blankets. That sight made her slightly sick: she knew it wasn't like that, but it seemed like someone had brought there three dead bodies and then forgot about them.

"The petrified students," she whispered. In the meanwhile Abigail extended a hand and knocked with decision on what seemed to be the foot of the nearest student, trying to test its solidity. Not happy, she moved forward and pulled down the blankets in order to uncover the faces of two kids, one after the other.

Feeling a sense of discomfort, Katerina stared at their bodies: they looked more like statues than real people. There was something strange about their faces, however.

"Damn, they really look as if made of stone," Abigail serenely affirmed, mirroring her thoughts.

"Abigail, look at their faces," pointed out Katerina. "Don't you think there is something wrong with them? We were told the sickness hits all of the sudden, but then why do Hammond and Finnigan seem almost terrified? They are not simply afraid or worried, look: they rather seem scared to death."

Abigail considered the disturbing expressions on their faces, and then uncovered also the third victim.

Her face was surely not relaxed, but showed what could be described at most as vague surprise, surely not terror. Weird.

Suddenly they heard the sounds of someone approaching, and they hurried to put the blankets like they had found them a few minutes before. When the nurse came in, Katerina tried her best to hide the guilty look on her face and promptly asked for the painkilling potion she needed.

While they were heading to the Potions classroom, Abigail and Katerina talked about what they had just seen.

"The Syndrome could cause the victim to hallucinate. Or maybe it slowly takes over, giving time to realize that something is wrong. At least it would explain their terrified expressions."

"Or maybe it's not a sickness at all," conjectured Katerina. Abigail didn't say anything.

They reached the classroom a couple of seconds before Professor Slughorn, who announced, to the extreme dismay of the Ravenclaws and Slytherins, that he had prepared a 'friendly' pop quiz to test their knowledge on the Strengthening Potion. Mentally thanking Merlin for her disappeared migraine, Katerina began to dispose pens and inkpot on her desk.

_Katerina Farley, Ravenclaw_, she gingerly wrote on the border of the sheet. _Theory of Potions, March the 5__th__, 1943_.

* * *

Library, again. Section of History of Magic, _again_. It was nearly the same scene as the night before, with a slight difference: the girl now wasn't avidly reading one of her books, but was dozing with her head resting on the wall. No one could sleep in that position and then wake up not wishing to tear off their neck, but, well, he surely wouldn't go and wake her up.

She was no Lauren nor Bonnie: her name was Katerina, as he had discovered that day following her around the castle. She was a fifth-year Ravenclaw, and in the morning she had attended Aritmancy, Potions and Charms, with a small deviation to the Infirmary. Clearly he lacked the means to spy on her during her lessons, but thanks to a useful little Locating Charm he had cast on her the night before he was able to find her wherever she went after each lesson.

Before dinner had been in the Library to write a essay; after dinner she had come back to the Library – original, really – but had fallen asleep right away. It was understandable that she was so tired, after what had happened the night before – not that she could remember any of it, of course.

For the umpteenth time, the Prefect told himself that it wasn't strictly necessary to look after her. But it was better that way.

There was still half an hour before curfew; in the Library a couple of dozens of students were still studying, and he was sitting at a table reading his notes on the Transfigurations lesson of that day, glancing every once in a while at the sleeping girl.

He was absorbed by a particularly nasty theorem on the Transmuting Spells, when he absent-mindedly happened to get a glimpse of the History section. What he saw, or actually didn't see, made him jump on his chair.

The girl was not there.

Cursing his distraction, the Prefect briefly wandered around to make sure she wasn't in the surroundings. Back to the table, he hastily threw together all of his stuff in the bag and rushed out of the Library.

"_Point me_," he whispered when he reached the first fork. The wand suggested to go upstairs. Surely the girl was too sleepy to study and decided to go back to her Common Room, he thought while he increased his pace. Nothing to worry about. But he needed to see her, to be _sure_, and then he could go back to the dungeons and stop thinking about it.

Maybe she saw him in the Library? Did she recognize him? No, it was impossible.

Following the instructions of his wand, he rapidly walked along an empty corridor on the third floor. The girl could not be far. Or maybe she could? How much time had passed while he was distracted by his readings? He really couldn't say.

He turned a corner and suddenly saw in front of him something that froze the blood in his veins.

The corridor was slightly dark. A few torches on the wall sketched shaking shadows on the barren stone; there were no paintings. It was the wing were the old Potions Lab was, he absent-mindedly registered; the old Lab that had not been used since the last Potions Mistress decided to move to the Dungeons. That place was abandoned; there were only empty classrooms.

And in the middle of the corridor the girl laid on the floor, motionless and wide-eyed, a cheek on the cold ground. A horrible gash ruined her face, forming a bloody wound on her neck. Her long hair surrounded her head like a halo. Her sweater was ripped in two, and the white shirt below showed an increasing red stain. The blood was everywhere: under her body, on the walls, on the window a few meters away. Vague trails of water could be seen on the floor.

Even as far as he was standing, the Prefect knew with absolute certainty that Katerina's heart was no longer beating.


	3. Light after dark

**A\N:** And the third chapter is here! I have a couple of things to tell you, but you'll find them at the end of this chapter. Thank you for reading! I remind you that English is not my first language, so let me know if you find any mistakes. Reviews are welcolmed with open arms.

**Disclaimer:** I don't own anything in the Harry Potter universe, it all belongs to J.K. Rowling.

* * *

_**From the previous chapter:**_

_He turned a corner and suddenly saw in front of him something that froze the blood in his veins._

_The corridor was slightly dark. A few torches on the wall sketched shaking shadows on the barren stone; there were no paintings. It was the wing were the old Potions Lab was, he absent-mindedly registered; the old Lab that had not been used since the last Potions Mistress decided to move to the Dungeons. That place was abandoned; there were only empty classrooms._

_And in the middle of the corridor the girl laid on the floor, motionless and wide-eyed, a cheek on the cold ground. A horrible gash ruined her face, forming a bloody wound on her neck. Her long hair surrounded her head like a halo. Her sweater was ripped in two, and the white shirt below showed an increasing red stain. The blood was everywhere: under her body, on the walls, on the window a few meters away. Vague trails of water could be seen on the floor._

_Even as far as he was standing, the Prefect knew with absolute certainty that Katerina's heart was no longer beating._

* * *

Katerina's body suddenly gave a start as if stricken by lightning, and she abruptly got up. Her hand rose to touch the lacerate skin on her left cheek, and she began to shiver. Her breathing was labored and she violently coughed a few times. Her disheveled dark hair, dirtied by dust and blood, covered her thin shoulders; she looked horrible, as if she was the only survivor of a catastrophic accident. She seemed a frail, broken porcelain doll, much younger than she actually was.

Slowly, from her throat came a chilling lament, while she covered her head with her hands to protect herself. She looked like an animal caught in a trap and severely injured.

The Prefect watched her shake and whisper something that sounded like _"no, no, no…"_. He sighed wearily: it would be a long night.

He felt simply furious, and incredulous. It wasn't supposed to go that way, it wasn't the conclusion he had predicted. She was not supposed to be there, in that moment and in that state, injured and scared. It wasn't right, not for her and especially not for _him_. He had done his best to make sure that things wouldn't take a bad turn, and yet here they were. He failed, and the fault lay in some stupid and unpredictable external forces. He wanted so badly to break something. But it would not help him; after all, he was about to start a conversation that was not easy to make, nor to hear. Breaking things wouldn't help make it taste less bitter. He remembered very well that time he had been in her place.

He couldn't say if he was angrier at the girl – because _come on_, no one could possibly be as unlucky as she had been – or at whomever had her in that mess.

"Hey," he curtly said, just to let her know he was behind her.

If possible, Katerina jumped even more violently than before. She turned towards him with a scared look on her face. She cautiously slid her legs to sit properly upon the desk she was on, one of the tables left inside the old Potions Lab. After seeing her, the Prefect couldn't help wincing slightly. Her face, usually smooth and round, was in terrible conditions. He leaned with his back against the wall and crossed his arms, waiting for her to stop looking around and assessing the situation.

"Who are you?", she asked at last. "What - what happened to me?"

"My name is Louis. I am in Slytherin. Sixth-year, and Prefect. Never seen me around?", he shortly said. The girl had a calculating look in her eyes. He couldn't say if she knew him or not, and she didn't answer. He kept looking at her for another brief moment: he had tried to remove some blood from her face, and it hadn't been enough.

"As for what happened to you, I'll tell you in a moment. We have a long conversation ahead."

"Why are my hands covered in blood?", she suddenly asked. "And why…" one of her hands touched again the rugged injury on her cheek and neck. "… oh no. _No_," she panted breathlessly. She started to struggle to get down the desk.

"Wait, wait! Be quiet. Your wounds don't matter now, they won't hurt you. Do you feel pain?", he quickly asked.

The girl slowly shook her head in trembling negation. Now she was looking at him wide-eyed, full of expectation. While he was waiting for her to wake up he had decided what to tell her, and how to tell her. He had tried to be calm and reassuring, because the situation was really delicate.

Well, now he didn't remember a word. What to say?

"There's been an attack," he finally said. She kept watching him, frowning.

"The Syndrome again?", she whispered.

The Syndrome? That sickness was certainly disturbing, but he wondered why she had associated it with the word _attack_.

"I don't know. It's a possibility," he admitted. "But this time the victim died."

"_What?_", she panted. "Who's dead?"

"Well, _you_."

The girl made a face that suggested he had grown another head or something. Louis sighed. It would be a really, _really_ long night.

* * *

Katerina felt forced to point out the obvious.

"You are wrong. I'm _not_ dead. I wouldn't be here talking to you, if I were," she said slowly, to make sure he would grasp the meaning of her words and understand his mistake. Of course, she silently told herself, I don't know where I am and what happened to half of my face, but I am surely not dead. He was probably joking, but she didn't find him funny at all: after all she had just woken up in a unknown classroom, without memories of how she had gotten there and _completely covered in blood_.

It was unreal; she must be trapped in a some kind of strange nightmare. She felt confused and terrified. The worst part was that she _knew_ that the blood covering her hands and face was hers. She wanted to Evoke a mirror to see in what state was her face, but she didn't feel brave enough to actually do it. And _why_ the hell did her wounds not hurt?

"Look," Louis started again with a slightly bored tone. "It won't be easy to understand what I am about to say, so please focus."

He moved away from the wall and sat on a chair, looking straight at her.

She watched him closely. At first she hadn't been able to remember where she had seen him before, but after his introduction she did. She knew him only by sight, however. He was tall, thin, with dark blond curly hair, and he was the Slytherin Prefect that had once deducted points to Abigail because she had crossed the corridor in front of him. What was his surname?

"Just tell me what happened to me, and what I am doing here," she said. All that fear was starting to make her feel annoyed. Couldn't he just tell her what was wrong?

"Alright, if you insist. That's the shortest part of our story. The last time I saw you alive, you were sleeping in the Library. I got lost in my thoughts, and when I looked again you weren't there anymore. So I went out the Library and began to look for you. I thought you were simply tired, and wanted to go back to your Common Room."

"That's right," she weakly confirmed, moving her legs again. They ached as if she had run a marathon. For a brief moment her head started to spin, and the room became darker. It was nearly empty – just a few desks and chairs all covered in dust. There was also a broken blackboard, with a few notes still written on it. All in all, it seemed no one had entered that classroom for a very long time. She tried to focus and frowned. It was right, she did fall asleep in the Library; then she had woken up with a start and a great pain in the neck, and decided to call it a night. Something of what the boy had just said sounded wrong, however. "But why…?"

"Why I was following you? I'll explain later," he curtly interrupted. "That's the most interesting part, by the way. So, I started to walk towards the Ravenclaw Tower. I found you in a corridor on the third floor, just outside the abandoned Potions quarters, that is where we are now. I hope you are aware that this place is not anywhere near your Common Room. What the hell were you doing here?", he asked. He almost sounded angry.

"I don't know," she answered defensively. Third floor? Abandoned quarters? She had no idea why she was there. And she didn't trust that boy at all: he had just told her that she was dead, for Merlin's sake. Or was it a threat?

"How can you not know?", he asked, then shrugged his shoulders. "Anyway, when I found you, you were in a very bad state. You were on the ground, covered in blood, and you were dead. I suppose someone or something attacked you. What was it? I had never seen wounds like that before."

Katerina, wordless, shook her head. Her mind kept to be blank. She couldn't grasp the meaning of what Louis was telling her; it felt like they were talking about someone else.

"Mh. In any case, I brought you inside this room and fixed the mess outside. And now, three hours later, here we are. Hope you enjoyed the story of how you died."

"Three hours?", she uttered. She felt the irresistible need to look at her wrist watch: it was true, it was past midnight. After a second thought she checked again: it didn't seem someone had tampered with it, and anyway, why would one do that? And now she had a hole of three hours that she couldn't explain. While she was furiously thinking, the words came out from her mouth on their own.

"You said you went towards the Tower to see where I was. Then how did you manage to find me, if we are so far from it? I seriously doubt you searched the whole castle. And anyway _why_ were you looking for me? I don't even know you."

Louis stared at her for a while, looking puzzled.

"I just told you I found your dead body in the middle of a corridor, and _that_ is what struck you the most?" His tone was genuinely perplexed. "You don't hear things like this every day. I admit I thought you would be more impressed. Or are you trying to find a loophole because you think it's all a lie? It's not, you know. You really died. And for the record, I'm not the one who killed you."

"Yes, well, you didn't answer my question."

"Alright, alright. The answer is: no, I did not search the whole castle. I didn't need that, because yesterday I cast a Locating Spell on you."

Katerina shivered from a thick pang of fear.

"What? Why did you do that?"

"Because I wanted to know where you were, obviously," said Louis raising a eyebrow.

This was too much. Katerina slid down from the desk and got up on her feet, looking at Louis with hostility.

"Listen, I don't know what you want from me, but I won't stay here any longer. You are clearly mad as a hatter, so please _just leave me alone_," she said sharply.

She strode towards the door. She was about to grab the door handle, but before her hand had reached its destination she was violently thrown in the middle of the room. She fell on the floor, hurting her back. Suddenly something terrifying stood between her and the door.

It was Louis, but at the same time it wasn't.

His eyes were red and blood-shot. The veins on his face were more visible than ever. From his throat came a low menacing growl, and his mouth showed unnaturally sharp-pointed teeth.

He stared at her. Katerina stood still, paralyzed on the floor by fear and surprise, and looked back at him, gaping. She could not move. She stopped breathing, and waited for the aggression that was about to come, for the feeling of those teeth biting her neck.

As suddenly as it had appeared, the monster went away, leaving only an ominous red glimmer in Louis' eyes.

"Not so fast," he hoarsely said. "We have a couple of things to discuss. Moreover, it's not safe to go around without this."

He calmly drew her wand from his pocket, and casually started to play with it.

"_What_ are you?", stuttered Katerina as soon as she felt capable to talk again. Louis smiled bitterly.

"I am the same as you," he answered, and then raised an eyebrow. "I am a vampire."

* * *

The girl's reaction, he had to admit, was priceless.

The expression on her face, a mix of fear and worry, became pure and unlimited horror.

That girl, Louis thought while he was waiting for her to overcome her shock, seemed a bit insane. Something inside her head made her shift without notice from a weak to an aggressive attitude, and vice versa. Like now, for example: in a half a second she wasn't a scared little puppy anymore, but stood up with an extremely serious expression on her pale face.

"When you say _vampire_," she started slowly, "you realize you don't make any sense, right? I would have noticed if I were a vampire. As for you, I don't know what's wrong with you, but if there ever was a vampire at Hogwarts he surely would not be still alive to tell the story. Therefore," she concluded, "I really don't – excuse me, does it amuse you?"

Hearing her speak, Louis had begun to smile broadly.

"Not at all," he said. He kept on smiling because he knew it unnerved her. "I just feel extremely pleased: I never realized how good I am at escaping the vampire police. Listen," he added in a more serious tone, before she could interrupt him, "I know it's hard to believe, but there are a few things I need to tell you, and then you _might_ find everything clearer. You won't go away from here any time soon. By the way, I thought it would be obvious, but clearly it is not, so let me explain: the door is spell-locked and your wand is in my hand, so, you see, you don't really have a choice. Now sit."

He watched her give up her rebel attitude and slowly sit on the same desk as before. She turned away from him and lowered her eyes to stare at her blood-stained hands. There was a moment of silence.

* * *

"It doesn't make sense," Katerina repeated, quickly glancing at the boy in front of her. "Vampires are Dark creatures. They are soulless and bloodthirsty monsters. Everyone knows that. You say you are a vampire, but you look… normal. More or less. If you don't consider what happened a few minutes ago."

"Thank you," he rolled his eyes. "Truth is, what _everyone knows_, as you say, is false or at least misunderstood."

"What do you mean?"

"Wake up, Katerina," he calmly said. "Wizards and witches aren't exactly famous for holding dear their magical minorities. Elves, mermaids, werewolves, vampires - to say that they are seen as subprime citizens is an understatement. Rules have been made, but the truth is that they don't want those minorities to be part of the wizarding world; they'd rather have them as far away as possible. No one was ever interested in trying to understand the real nature of these people. Just think about all the prejudices against the Muggleborns, and _they_ are exactly as human as the Purebloods."

"Are you saying that all we know about vampires is just unfounded rumours?", she asked, skeptical. In spite of everything, her Ravenclaw spirit found that idea quite interesting.

"Not quite," he admitted. "What I am saying is that we are soulless and bloodthirsty monsters, as you kindly described us. Well, not really _soulless_, even if sometimes we feel a little bit like that. What I want you to understand is that wizards don't really know anything about vampires. They are afraid of us, and their fear caused wars and death all over the centuries. Hence vampires prefer to live far from them, to stay in the shadows and never reveal themselves. Just like the wizards had to hide from the Muggles before the Statute of Secrecy."

"You make it sound like the _vampires_ are the victims. But vampires are cruel, and have to kill people to survive; there was a _reason_ for all the fear and the fighting," she retorted, then closed her mouth. A quick thought made her realize that maybe it wasn't a good idea to anger him. Anyway, he just shrugged.

"No one is ever completely a victim," he simply said.

"But you don't stay in the shadows. You live in a school full of people," she calmly observed, recalling what he had just said.

"I do. I managed to keep going to school because I took advantage of all the preconceptions. No one ever realized what I am because no one really _knows_ how to recognize a vampire. To the untrained eye, I am just another one of the hundreds of students living here. You should be grateful, because from now on you'll have to hide in the crowd too."

Ignoring his last sentence, she mused, "I can't believe no one ever studied vampires. We've had a great number of researchers over the centuries; at least one of them _must_ have studied Dark creatures. For example Newt Scamander is known for…"

"Someone probably did, but it was not enough – just another voice in the chorus," he interrupted her.

"But we've been taught this things at _school_. We studied vampires in our third year."

"And as you are a Ravenclaw, discovering that school teaches something wrong horrifies you. I understand. I'm sorry, but it's the hard truth."

His tone was jokingly solemn, and she let out an unsure half-laugh. His posture seemed more relaxed, now that they were speaking calmly. His grey eyes had some kind of twinkle that had nothing to do with the menacing red glimmer she saw before.

"Come on, tell me what you think you know," he said crossing his arms.

"Well, actually - it's what I said before." She hesitated. "Vampires are Dark semi-human creatures. _Undead_ beings. They need to drink human blood in order to survive, and they often kill the victim they feed on. They have some sort of mental power, which they use to bewitch people. Garlic repels them, wooden stakes kill them."

Louis nodded, then raised his fingers as if he was counting.

"Well, you got almost right the feeding and killing part. We are actually dead, it's true. We don't really have to drink blood to survive, because we can't starve to death, but I assure you don't want to meet a hungry vampire. The curse on us is so powerful that we can never die, unless we are staked directly in the heart by something made of wood, or beheaded. We don't age, we don't get sick. It is said that thousand-years old vampires still live somewhere in the world."

Katerina couldn't stop staring at him. It was fascinating.

"We don't always kill our victims; some of us do, others don't. It's up to personal taste, I suppose. Finally, garlic is completely useless, even if it's funny to make people believe the opposite. No, what really is toxic is vervain; you know, a plant."

"How do you become a vampire? Do you have to be born one?", asked Katerina curiously.

"No, you don't have to be born." He stopped for a moment and stared at her as if he was wondering something. Then he started talking again. "There is only one way to become a vampire: you have to die shortly after ingesting the blood of another vampire."

* * *

Katerina seemed to ponder his last sentence, while inside her head some alarm bells were probably starting to ring. Louis watched her put two and two together.

"So I – you told me that now I am a vampire. You told me I died – and I think I believe you, even if it sounds crazy," she sharply said. "When did I ever drink the blood of a vampire? Why should I have done something like that?" She frowned. "Why were you following me tonight?"

Louis was sure she wouldn't take the truth very well.

"Katerina, I've been following you for a week. I saw you in the Library a while ago and I realized you were always alone. You stayed there for hours, studying on your own, sometimes even after curfew. I took some time to be sure, but then I decided that no one would have noticed if you went missing for a while."

She was agape, her breath faster and faster.

"What did you do to me?" she whispered, horrified.

"Last night I waited until the Library was empty. I had cast a Lessening Spell to make sure no one would bother you, and that you wouldn't realize how late it was. I Stunned, Disillusioned and Levitated you in a safer place."

Katerina was as pale as a ghost.

"You – you fed on me?", she uttered, her voice higher than usual. She took a few steps backwards, to distance herself from him. Louis shrugged.

"You were the perfect victim. It was nothing personal; if it weren't you, it would have been someone else."

"But I can't remember any of this!", she yelled, putting a hand on her head. She looked about to break down and cry. "I woke up in an empty classroom, covered in blood – you tell me I'm dead, that I became a vampire and – and are you telling me I was attacked two nights in a row by _two different people_?" She put her hands on her hips, watching him angrily. "I seriously doubt that. No one could ever be that unlucky. It was _you_ both times."

"It wasn't me," Louis sighed. "But you have a point. It's absurd how unlucky you are."

"I don't believe you," she hissed, while tears started streaming down her cheeks. She strode towards the door, passing beside him. "Why should I trust the word of a vampire? Let me out!"

"You are not going anywhere," he firmly retorted.

Katerina looked at him, her face full of hate. Suddenly she raised her fists and started to hit him on his chest.

"Let – me – out!"

Hitting him again, she reached out one of her hands to grab her wand in his pocket, but Louis caught her wrist.

"Stop! What the hell are you doing?!"

The girl tried to hit him in the face with the other hand, but he caught that too. Now both her wrists were trapped in his hands, but she uselessly kept struggling to free herself.

"_Stop!_" He violently shook her, and she seemed to freeze. He lowered his head to angrily look in her dark eyes.

"Now listen to me, you insane, lunatic fool. You can get mad as much as you want, but that's what happened. I didn't lie to you. I attacked you the first night, but not the second. _Yes_, I drank your blood. You don't remember anything because you were Stunned most of the time, and when you woke up I changed your memories in order to make you forget me. I don't care if you are too prude to understand, but we'll see what you do when the thirst will have you jump at the jugular of the first poor bastard you meet."

He venomously shook her again and then freed her. She immediately made a step backwards, contempt in her eyes.

"If you only drank my blood, why did I ingest yours?", she asked angrily. Louis crossed his arms.

"The blood of a vampire has highly healing properties. It has to, because the immortality spell is cast upon it, hence it can rapidly heal us when we need it. I knew I couldn't just send you back with those injuries on the neck and less blood than you should have had, so I gave you some drops of my blood to heal you. But damn, I should not have done that." He kicked the nearest chair and it broke. "Vampiric blood stays in your system for twenty-four to forty-eight hours at the most, so I simply decided to keep an eye on you to make sure you wouldn't have yourself killed and become a vampire. You weren't the first, you know; I did it more than once. I was so _sure_ you would be fine – you don't often hear about dead students at Hogwarts, after all," he bitterly said. Now he felt the same fury as before, when he had found Katerina dead on the floor. "But no, in five minutes' time you managed to go away on your own and have yourself murdered. It wasn't supposed to go like that!"

Katerina opened her eyes widely.

"Now it's _my_ fault?", she shouted. "What do I have to do with you being a lousy bodyguard? I didn't ask you to attack me. I did nothing to you – we never even spoke to each other! You could just leave me alone, and none of this would have happened!"

"Oh I don't think so. You should thank me, to be honest! I wasn't the one who killed you, remember? If I hadn't given you my blood you would have died and never come back to life, so there. You wouldn't be here yelling and shouting, you would just be _dead_. Much a smaller problem, if you ask me," he concluded in a hateful tone.

"Just let me out and I won't be your problem anymore," she gelidly retorted.

"Yeah, right. Don't be silly. If they find out about you, they'll find out about me too. Maybe wizards don't know us very well, but they are perfectly capable to put two and two together, should someone attack them for their blood. I'm not going to be caught because of you, so now calm down and think." He grabbed her arm and lowered his voice. "I know it's hard to accept, but this is what you are now. You can deny it and die now, or you can _survive_."

Katerina stood there, unmoving.

"I don't want to die," she reluctantly whispered after a few seconds.

"Then listen to me. No one, and I say _no one_, will have to know what you have become. They wouldn't understand, Katerina. They'd kill you without thinking twice. You'll have to be careful, whatever you do. Promise me." The girl didn't say anything. "_Promise me_ you won't put us in danger."

"I promise," she slowly said.

"Good. Now drink this," he told her, Evoking a closed red phial. He handed it out to her. Katerina took it and opened it. Its content was a dark red liquid that tickled her nostrils.

"Is it what I think it is? Blood?"

"Of course."

"Whose is it?"

"You don't need to know. Now think about it, Katerina. You are now in a transient state between human and vampire: this is why your wounds haven't healed yet. You are nor the one nor the other. If you drink this blood you'll complete your transformation and become a vampire; if you don't, you'll die for good in a few hours. The choice is yours."

"Why are you telling me this just now?"

"It wasn't important," he frowned. Katerina watched him closely.

"Maybe you thought you could just keep the blood for yourself and let me die, if I were a threat to your secret," she accused him.

"Even if you drink it now, don't you ever think I wouldn't be able to kill you," he answered raising his eyebrow. But he didn't deny.

Katerina didn't say anything to that. She kept the phial in her hand as if it was a bomb about to explode. She stared at it with caution and fear. Finally she began to raise it towards her mouth, but then hesitated, and lowered it down.

* * *

**A\N part 2:** so yes, this is a story about vampires. I'll try my best to keep them consistent with the Harry Potter universe, but I think they fit in rather well. You may have read something that sounds familiar: I imagined a few things on my own, but I borrowed something from multiple sources, mainly _The Vampire Diaries_. You don't need to know anything about it because I'll explain everything in the story - well, I mostly already have.

The protagonist's name, Katerina, is a nod to one of the characters in _The Vampire Diaries_, namely Katherine Pierce. They have nothing in common save the name. Furthermore, Louis owes his name to Louis de Pointe du Lac, a character in Anne Rice's _The Vampire Chronicles_.


	4. Hidden

**A\N:** Hello! Thank you for reading. I remind you that English is not my first language, so let me know if you find any mistakes. Reviews are welcolmed with open arms.

**Disclaimer:** I don't own anything in the Harry Potter universe, it all belongs to J.K. Rowling. If you read something that remind you of _The_ _Vampire Diaries_, then it probably comes from _The Vampire Diaries_.

* * *

**_From the previous chapter:_**

_"Is it what I think it is? Blood?"_

_"Of course."_

_"Whose is it?"_

_"You don't need to know. Now think about it, Katerina. You are now in a transient state between human and vampire: this is why your wounds haven't healed yet. You are nor the one nor the other. If you drink this blood you'll complete your transformation and become a vampire; if you don't, you'll die for good in a few hours. The choice is yours."_

_"Why are you telling me this just now?"_

_"It wasn't important," he frowned. Katerina watched him closely._

_"Maybe you thought you could just keep the blood for yourself and let me die, if I were a threat to your secret," she accused him._

_"Even if you drink it now, don't you ever think I wouldn't be able to kill you," he answered raising his eyebrow. But he didn't deny._

_Katerina didn't say anything to that. She kept the phial in her hand as if it was a bomb about to explode. She stared at it with caution and fear. Finally she began to raise it towards her mouth, but then hesitated, and lowered it down._

* * *

Katerina cautiously stared at the phial in her hand. It undoubtedly smelled like blood, but for some reasons it didn't irk her senses at all; on the contrary, it was a strangely tempting smell, just as intriguing as the sudden sight of food in front of a starving man. But she couldn't force herself to drink it, even though Louis was very clear: if she didn't drink, she would die.

She kept looking at the blood, suddenly wondering what would be her father's advice in that circumstance. A clear image of him appeared in her mind: tall as a giant, with kind and reassuring dark eyes. She didn't have many memories of her father, but in one of them she remembered him taking her in his arms and telling her to be always careful. Growing up was a wonderful but dangerous thing, he had said, and she had better learn not to blindly trust everything around her, because appearances might not be always truthful.

That phial, with its alluring smell and irresistible promises, kept inside everything that her father had warned her about. But now her father wasn't there to explain to her what was right and what was wrong, like he did when she was a child. He would have known what to do, but she didn't, because she hadn't heard the sound of his voice for too many years.

She raised again the phial toward her lips and warily drank a little sip. It unquestionably tasted like blood, but with a disturbing thought she realized she didn't find it disgusting at all. It felt like drinking a cool fruit juice after the burning heat of the desert.

Her instinct commanded her to drink again, and she did. When more blood filled her throat, its pungent taste almost choked her and forced her to cough a few times, smearing her hand and chin.

"Slow down," Louis warned her with a slightly bored tone. "Don't worry, it's normal. You are turning into a vampire, and your body is not ready to take blood yet. Try again."

When she was able to normally breath again, Katerina restarted to drink, now slower. Within a few seconds, however, the phial was empty.

It was an odd feeling. Her bones were burning more and more with a sudden strange aching. She absently noticed that her hands were relaxing, and a sound of broken glass seeped through her foggy mind to let her know that the phial was now on the floor.

Her head started weakly spinning. The lights in the room were much brighter, and she had to blink a few times to fight the annoying feeling of the light burning her head on the inside. Her ears were now detecting a dull, throbbing sound that she had never heard before, and that seemed to come directly from her veins. She blinked again, but her sight was now blurry; everything – the tables, the chairs, Louis' unreadable eyes gazing at her – was unfocused. So she just closed her eyes, leaning on the desk to stand steadily, and trying to ignore her aching legs. She had been cold before, but she hadn't realized until she felt warmth on her cheeks. She was tired too, she noticed, and suddenly hungry; or maybe she was thirsty, she couldn't tell the difference. It was some kind of throbbing pain in her stomach that made her mouth feel like full of sand.

She opened her eyes. Louis was still staring at her closely, carefully watching every one of her movements.

"I feel exhausted," she weakly said.

"You'll be fine," simply said the boy.

His words had a weird echo, she thought; or maybe it was his voice that sounded different. No, it was _her_ that listened differently.

The pain in her stomach was stronger and stronger. She couldn't take it anymore, but something inside her was telling her how to exactly make it stop, and she couldn't help thinking about it.

"Do you have more blood?", she said, a bit unwillingly.

"Not here, I'm sorry. But I have something else that might help you."

As before, Louis Evoked a red phial and gave it to her. Katerina smelled its content and grimaced: even if it didn't smell bad, her brain registered that there was something unnatural, wrong. She didn't know what it was, yet if she had to chose a word to describe that liquid she would have used _rotten_. But the increasing pangs in her stomach were becoming unbearable, so she held her breath and drank it quickly. Her thirst subsided at once, while the tiredness didn't leave her bones.

"You just drank a conveniently modified Blood-Replenishing Potion. Instead of replenishing the taker's blood, this version partly reproduces the effects of human blood on vampires. It's nothing as the real thing and it loses its effect after a while, but at least it temporarily mitigates the thirst. It's not difficult to make; I'll teach you how to do it."

"Did you invent it?"

"No," he snorted, amused. "I suck at Potions. Someone taught me to produce it."

Katerina didn't say anything, but kept staring at the phial, feeling numb. Her mind was filled with weariness and confusion. A slight tinge of depression started to creep up on her when she thought that the bottle in her hand contained something she would have to depend on forever. She also had the feeling she was in shock.

"I can't believe it," she murmured. "I just drank blood - _real_ blood. I am a _vampire_."

"It's not that special, you know. It involves a little bit of blood stains and murderous feelings, but with a bit of practice you can hide all the symptoms."

"Symptoms," she repeated. "Like a disease."

"Yes, sort of. Look at it this way: you got terminally ill of vampirism. The good news are that the _'terminally'_ part is already gone."  
Oddly, the idea seemed to entertain him.

"I don't – w-what should I do?", she asked, and winced when she felt the note of desperation in her own voice. "I believe you, but this is too much. I can't just forget everything and go on as if nothing happened."

"In fact you won't. You made your choice, you can't go back to the life you had before," Louis sharply retorted, and then added in a softer tone: "But you'll manage. It isn't easy for anyone at the beginning, and it will take time, but you'll learn how to live as a vampire. For the here and now, let me tell you exactly what you will do in the next few hours. Now you'll go back to your Common Room, before your roommates realize you haven't returned yet. You will behave in a perfectly normal way, as if _nothing_ happened. Try not to be too close to other people, because you may have a sudden urge to attack them and you haven't learned to control yourself yet. Then, you'll have to find a way to stay hidden all day."

She jerked her head up, looking at him bewildered.

"As you may know, the direct light of the sun can incinerate a vampire. It's part of the curse cast on us, and I assure you it's extremely inconvenient. What you don't know, however, is that there are ways to bypass the problem and walk in the sun like everyone else. I'll take care of it, but I need some time to get the correct spell – a day or two, I think. Until then you'll be careful to stay away from the light – direct light, so if you are in some room inside the school you should be fine. Unless you want to burn alive, that is. And Katerina… I remind you you live in the highest tower in the castle. This means you'll have to leave your dormitory before the sun rises, and stay far away from it until dusk."

"I can't just stay hidden all day!" she snapped. "I swear, I'll be careful not to get hit by light. Don't you think someone would _notice_ if I just disappeared?"

"Then find a credible reason. You are a Ravenclaw, use your brain," Louis retorted shortly. "I think they would notice you more if your skin inexplicably started to be covered in burns. Trust me: avoiding the sun is more difficult than you think. Even the ceiling in the Great Hall could kill you, if it's sunny outside."

"Killed by a _ceiling_," Katerina muttered.

"Indeed, by a ceiling," Louis repeated in a sarcastic tone. "You are not planning to die twice within twenty-four hours, aren't you? I wouldn't even be surprised."

"You stay away from me and I'm sure nothing bad will happen to me."

"Don't get your hopes too high. _I_ will decide when to stay away from you," Louis hissed menacingly. "You don't know what you're getting into, and you have absolutely no idea of what's waiting for you. Just remember you came back as a vampire only thanks to _me_, and you should be grateful that I didn't decide to kill you at once afterwards, even though you are a huge risk. If you are discovered they will begin looking for vampires all around the castle, and I'm not going to stay hidden all my life because you were too dumb to do as you were told."

"Then why didn't you let me die?" she icily asked.

"I was tempted to, but it's not a great idea to leave around human bodies with vampire blood mixed with theirs or, even worse, dead vampires. We don't want to draw attention on something that should stay secret: it's much better to arrange things in a way that nobody realizes that something has changed. But I swear on everything that's sacred in this world – make one mistake, Katerina, and I _will_ kill you."  
His tone was deadly serious.

* * *

Since she had gone back to her dorm, a few hours before, Katerina had kept shifting and turning on her bed. The only idea of falling asleep seemed ridiculous. She laid down on her back, a hand on her chest. Did dead people sleep, anyway?

Because that she was: dead. It sounded completely illogical, a strange thought that she could not relate to herself. Less than twenty-four hours ago she had woken up alive, without a care in the world except a stupid headache – that was caused by a forgotten loss of blood, it was clear now. If only she had a Timeturner she would go back and tell herself – what? Maybe something similar to _'this is the last day in your life'_. Perhaps she was destined to die – the sand in her metaphorical hourglass would stop to flow in any case – but at least she would have known. She really would have preferred to know.

She had never thought much about death before, but she surely had never imagined to still be able to walk around as if nothing had happened. Certainly not like Professor Binns, whose career was still quite active thanks to his indifference toward everything. But he was a _ghost_, and ghosts weren't difficult to understand; it didn't matter how much weird and unsettling they could be, in the magical world they were still part of the order of nature, just like ghouls or the rivalry between Gryffindor and Slytherin.

But now that she was alone, in the total dark of her bed, lulled by the sound of the gentle breeze that caressed the Ravenclaw Tower, she had to admit that something had changed. _She_ had changed, unexpectedly and without noticing. A minute before everything in her life was fine, the next she was injured, covered in blood and hostage of a vampire. And surprise, now she was a vampire too. Her personal world had crumpled and was now just ashes under the shoes of the people that had hurt her.

Her hand pressed her chest again. While she was still alive she had never been aware of it, but now that her heart had stopped beating she realized how much she missed it. It was an incessant hole, a heavy burden that took her breath away and made her desire to scratch and dig and pull her heart out to see what was wrong. For a long moment Katerina begged her heart to restart, to throb again and pump the blood in her veins. Nothing happened. She was dead.

It was the real reason why she had started to believe Louis' words: she had literally listened to her heart.

Eyes wide open in the dark, Katerina focused on the sounds around her. She heard quite clearly her roommates breathing, as if they were lying at her side. They seemed deeply asleep. In the silence of the room, she could also hear the asynchronous beating of their hearts. If she concentrated hard enough, she found out she could even tell apart what was outside the bedroom. Paces in the Common Room – someone was awake, and was apparently walking in circle. A far, stifled sound – she associated it with the murmur of the plants in the Forbidden Forest. Someone who was turning in his bed. A bird spreading its wings in the night. A laughter in the distance, piercing the air with its never ending vibrations. The sudden suffocating sound of dozens of people living breathing moving inside the Tower –

She put her hands on her ears, shocked. She could hear _everything_. She hadn't been ready to welcome a thousand sounds inside her head, so she desperately tried to keep them all out. Maybe the trick was to not think about it. She closed her eyes and tried to focus only on one single sound – her breath. Slowly, it seemed to work.

Now that she was a damn vampire, her sense were apparently much more sharpened than before.

She thought again of the night she just had. A few hours before, after Louis had finally let her go with hundreds of warnings, she had walked towards her Common Room as if lost in a dream. Luckily she had not met anyone along the way, and in a blink she was inside the Tower. She had stared at the empty room for a while, unmoving, and then she was standing in the bathroom looking at herself in the mirror. She didn't see anything she could recognize, even if the figure in the mirror had her long hair, her dark eyes, her worried face and the same features she had always seen.

"Seen a ghost?", had said the mirror making her jump. She hadn't answered; instead she had took a quick shower to clean herself from all the dirt and blood.

Abigail was awake, and had asked in a low voice where she had been. _I fell asleep in the Library_, she had answered, and it wasn't even a lie.

Remembering the mirror, Katerina gently touched her face and her neck. Her skin was cold and smooth; there was no trace of the scary wound she had felt before drinking the blood. It was like it had never existed, as if all that had happened that night was just part of some strange nightmare. Yet the truth was different, as she knew very well: it _had_ existed, but the vampiric magic in her blood had already healed every injury, like Louis had said.

_Louis_. They had never talked to each other before, but of course she had seen him around the castle, with his short dark blond curls and some of his fellow hateful Slytherins on his side. She didn't remember what his surname was, even if he was a sixth-year Prefect. It wasn't surprising: she knew quite a lot of students from the other Houses, but only a few from Slytherins – only the ones in her year, in fact.

While the rivalry between Slytherin and Gryffindor was more or less personal, the rivalry between Slytherin and Ravenclaw was principally intellectual. The Sorting Hat sent smart and curious people to Ravenclaw and smart and ambitious people to Slytherin, so those were the Houses whose students usually fought the most to achieve better grades at school. The mixed Ravenclaw-Slytherin class of the current sixth-year was especially famous for taking drastic measures in order to keep members of the rival House from gaining points during lessons, to the point that the Professors were forced to raise magical walls to prevent the two groups from sabotaging each other's potions or from mutually setting their wands on fire. It was open warfare.

But after what happened that night, after all, the struggle for grades had lost importance. Louis' only concern seemed to be finding a way to prevent Hogwarts from discovering about their presence. She could understand him: public opinion said that vampires were one of the worst kind of Dark creatures, inhuman monsters ready to slaughter everything that breathed. She honestly couldn't say if public opinion was right or wrong; however, she was sure that any wizard would not hesitate to kill a vampire should they see one. Even if for some sort of miracle she was allowed to live, Headmaster Dippet would never let her stay at Hogwarts; she was too dangerous for the other students.

Was she making a mistake? Remaining in a suddenly hostile school – to which she was a potential danger – looked like a terrible idea.

With a pang in her heart – that mockingly remained motionless – she wondered what she would do when she got thirsty. Louis had given her a few phials of modified Blood-Replenishing Potion to drink when she felt the need, but she was still afraid of what would happen. She felt lonely and scared. What would she do if the next day she was immediately discovered?

From an impersonal point of view, she was surprised that Louis ha let her "live"; he looked perfectly capable of killing someone without thinking twice. She knew she was a gigantic threat for him: having another vampire around meant doubling the chance of being discovered. Moreover she was inexperienced, and the boy didn't know her; he couldn't know how she would react to all that undead-thing.

But as he had said, probably leaving bodies full of vampire blood around was a suicide. She imagined that that sort of Dark components would leave a trace perfectly clear to the Aurors or the Healers; vampiric blood would leap out like a dragon inside a drawer.

The best solution, she dispassionately reasoned, was to kill her at once and hide her body. But in that case her disappearance would have drawn the attention of the whole school; investigations would have been made to find out what happened to her, maybe discovering things that Louis preferred to keep buried.

No, letting her live was actually a risky move, but at the same time there was a chance that everything would go well and nobody at Hogwarts would ever hear about vampires.

Thinking about Louis caused an unpleasant feeling in her stomach, a pang of anger that she struggled to fight. Despite all of his chatter about her being alive only thanks to him, he had done something _terrible_ to her. He had attacked her, bitten her and erased her memory – she was actually thankful for not remembering those hateful details, but she would certainly never tell him so. And yes, she was alive because his cursed blood had brought her back to life, but he had been very clear – it was an accident; she was a mistake. She wasn't supposed to survive.

Who knew, maybe if she wasn't so tired after his attack she would have left the Library at another time, escaping her fate. And anyway he was supposed to keep an eye on her exactly to avoid that sort of things, but he failed. Maybe he didn't take that job very seriously.

There was also another big, enormous problem that had her thinking. That day someone or something _had_ _killed her_, maybe accidentally or maybe not. That thought would normally shock her, but after the day she just had she found that nothing would ever be the same. She felt cynical, and maybe that was a good thing: ingenuity had not kept her alive.

It didn't matter how much she tried – she couldn't remember that fatal attack, nor the face of her killer. She only knew that the next day someone might be greatly surprised to see her. She hoped she was able to handle it.

Dear Merlin, and to think her usual nighttime troubles concerned homework or tests in class.

* * *

Katerina sighed, watching the sun rising in the distance. She was in the Library, in the Section of History of Magic, her favorite place in the castle. She was extremely careful to stand in the shadows, at a safe distance from the great window. After all she was trying to hide from the light, just like Louis had told her.

She had sneaked off the Tower before dawn, trying to be quiet but without too much effort. She actually could make much less noise than that, but she needed to wake someone to whom she could lie to. Abigail, who was a light sleeper, predictably asked her in a sleepy voice where she was going, and Katerina told her she would visit the Infirmary because she didn't feel very well. It was a stupid excuse, she knew that, but she couldn't think of other lies that allowed her to get up so early and to miss her lessons. It was a long shot, and soon she would have to think of something better.

Clearly, she had no intention whatsoever to go to the Infirmary for real. That room was far too illuminated, and she bet that Madam Wainscott could figure out that something was wrong with her in less than a minute. Now that she thought about it, she would have to stay away from the Infirmary for the rest of her career at school: it was too dangerous.

After leaving the Tower she had not known where to go or what to do with herself, so her feet had automatically brought her in the Library.

Standing there with crossed arms, she watched the light flooding the halls, enlightening the shelves next to her. After a brief hesitation, she slowly stretched her hand to touch the light, hoping that maybe -

She had to cover her mouth with her other hand to suffocate a shriek.

The light had covered her fingers for just half a second. Horrified, she stared at the ugly blisters that were forming on her trembling hand. The skin was red and burned. It was so painful she wanted to cry. And then, after less than ten seconds, her fingers suddenly started to heal, and after that there was no trace of burns at all. She incredulously looked at her hand, turning it in front of her eyes a few times. It was as pale and smooth as before. She gently touched it. The pain was gone.

So, the place she felt the safest in all Hogwarts was apparently off-limits.  
She suddenly wanted to cry.

Yet she didn't, because she knew it wouldn't help her.

Depressed, she quickly left the Library and tried to avoid all the enlightened areas, reflecting on how weird her zigzag route would appear to a casual observer. Luckily there was no one else to see her – she only met the ghost of an old woman who didn't even give her a second look, as if she was completely invisible.

She was safe in the inner corridors, while she avoided the ones with windows. She knew she had to keep distant from the Great Hall. The spells reflecting the weather outside must be really powerful, she mused; but after all, they said it had been Rowena Ravenclaw herself to perform that magic. For the first time since she was at Hogwarts she wished her Founder wasn't so intelligent.

She decided to head towards the dungeons, wondering if she could stay in the kitchens for a while. It was still early, but not so early that she would be punished if someone found her wandering around. Anyway there was no one to be seen, so she walked undisturbed.

She walked past the entrance of the dungeons, but then she suddenly decided to make a detour from the main route. She had to find a way to distract herself, after all; she had all day ahead. At least she could wander in the dungeons without risking to be hit by the light of the Sun.

She didn't knew that place very well – the truth was she avoided it like the plague, unless she had Potions. Maybe she could spend the last two years and a half at Hogwarts hiding in the dark of the dungeons, scaring students away and brewing potions like the Cure for Boils or something as unpleasant.

Walking had a positive effect on her. While she was exploring the dusty corridors, undisturbed, she could ponder on the events of the last days. The dungeons were so big she could even get lost inside them – she may enter and never come out again.

She was so deep in her thoughts that a sudden crack in the wall beside her made her violently jump. The stones were relentlessly moving, making a noise so loud that her now sensitive ears hurt. She turned to face what was happening and saw a boy in front of her, where just a second before there had been no one – it was Louis.

She felt a cold shiver running down her back, as she watched his grey eyes blankly staring at her. She made a step backwards. Fear was blocking her tongue and draining her breath. She didn't expect to see him so soon – she wasn't _ready_.

A glimmer in his eyes, and then he smirked at her, perceiving her fear. He put a finger on his lips to suggest her to be silent, and he quickly glanced behind him, blonde curls shining in the light. She followed his gaze and saw a glimpse of a rather large room made of stone and a fire blazing in the fireplace. She gulped. Apparently, in her careless wandering she had reached the Slytherin Common Room.  
He turned again towards her. He seemed ready to say something, but then he changed his mind and looked at her as if considering something.

"_Play along_," he whispered after a moment. Then, before she could even try to understand what was going on, he said loudly:

"What a nice surprise, a solitary raven at our doors! I always thought you Ravens had your nose so up in the air that you weren't even capable to find the entrance of the dungeons."

His tone was contemptuous. Katerina blinked, uncertain, and then replied:

"Oh, we know where it is. We just avoid it because of the stink."

She raised her eyebrow. Louis smirked again, this time in a challenging way. In the meantime a few other Slytherins had come out from their Common Room to see who was making all that noise. Louis stepped into the corridor to make space for his housemates, and then pulled out his wand.

"Don't they tell you, up on your perch, that it's not polite to go to other people's houses and insult them? Five points from Ravenclaw for your baffling bad manners, Miss," he said with a satisfied sneer.

Katerina watched him agape. She didn't know what he thought to accomplish, but – _had he just taken points away_ _from her_?

Meanwhile, the other students were snickering, and she felt herself reddening for the anger and the embarrassment. She really just wanted to run away from that horrible place. But now Louis was staring at her and was moving his lips to whisper something that sounded like "_curse me_". What?

Well, she didn't need to be told twice. She said, "I'm afraid this day was already awful even before your interference," and calmly pulled out her wand.

"_Incendio!_", was the first spell that came to her mind. Louis faked surprise, but blocked easily her spell and then raised his wand towards her with an unreadable expression on his face. His housemates, instead of stopping the fight or helping him, started to merrily talk to one another and moved to surround them – some of them jostled their neighbors to have a better view, and then began to cheer loudly. Katerina had the odd feeling that those sort of fights actually happened quite frequently, down there.

"_Incarcerous,_" said Louis with a lazy flick of his wand. Katerina created a Shield to block it, and felt her magic slightly tremble at the collision with his spell. She raised her eyebrow, trying not to let her surprise show too much. Louis moved with self-confident grace, and even if he had only cast a basic incantation, she had perceived more power than she had expected. He looked quite skilled with spells.

She thought about all this in a brief moment, and then performed a nasty Bat-Bogey Hex. They weren't exactly mortal blows, and she heard disappointed sounds coming from the audience.

They kept dueling for another minute or so. They never hit each other – but not because of lack of trying. It was almost infuriating: she was trying everything she knew, while he didn't even seem to put so much effort. But then their eyes met, and something in his gaze let her know that she shouldn't defend herself from the next curse.

"_Lux Exumain,_" she heard.

A flash of black light hit her fully in her stomach, forcing her to bend and erasing her breath. It wasn't painful – she only felt an annoying prickling on her skin. She heard the Slytherins exult and laughing at her. Luckily, Professor Slughorn chose that moment to check the origins of that turmoil.

"Boys, what's going on here? I hope it's not that illegal fighting club again – _oh dear_," he worried, seeing her there. He spoke towards his students. "This is no way to treat a lady. Now off you go, there is nothing to see here!"

While the others unwillingly started to walk towards the Great Hall, the Professor spoke again. Louis had come near her, and had an amused glimmer in his eyes.

"I thought I told you quite clearly, Mr. Henry, that if you were caught cursing one of your Ravenclaw fellows again I would have to take measures. What did you do to our poor Miss Farley? No, don't tell me." He didn't even sound angry, only resigned. "I recognize the bluish halo. Again a Photosensitivity Spell, am I correct? I really don't see why you find this charm so funny. I am forced to give you a detention; come to my office tonight at seven o'clock. My dear," he then told Katerina. "I am afraid there is nothing we can do, except waiting for the curse to run out of your system. This spell makes your skin really sensitive to light, but it's only temporary, don't be afraid. Now, we shouldn't let you leave the dungeons, or you'll be in a terrible discomfort."

"But Professor, I have lessons to attend," Katerina said. She was starting to understand what all that mess was about.

"Nonsense," he said loudly, moving his hands up and down. "I will explain the situation to your Professors. Which lessons do you have today?" Katerina told him. "Right, right. You are excused, but only for today! In the meantime you can stay in my office. As you dueled in the corridors, your detention will be to brew three cauldrons of Cure for Boils. That potion is too popular in this school," he sighed.

While Slughorn started to lead the way, Katerina briefly turned towards Louis, who made a dramatic bow. She watched him almost shocked and then shook her head, amused.

* * *

The rest of the morning went by without any extraordinary events, except when she almost blew a cauldron up because she confused the jar of horned snails with the one of eel eyes.

Brewing the Cure for Boils was without any doubts long and boring, but at least the Photosensitivity Spell gave her a good excuse to stay hidden all day. The prickling on her skin was still present, but it was nothing compared to what the light had done to her hands before.

What really worried her was the hunger she felt. She didn't have breakfast, but she doubted it was the lack of tea and biscuits to cause all that pain in her stomach. When her hands started to tremble and her sight to become fogged, she Evoked one of that phials prepared by Louis and drank it. She felt better, but she didn't know how long it would last.

After she finished brewing the potion, she decided to examine the books on the shelves in Slughorn's office. Most of them were old and worn out, but one in particular drew her attention. She pulled it out, opened it at the right page and started to study the Blood-Replenishing Potion and its variants.

The Professor came back a few hours later, praised her work and ordered the houselves to bring her lunch. When he asked her how she felt, Katerina, who hadn't felt the effect of the spell for a full hour, lamented an unbearable prickling on her skin. Slughorn nodded and invited her to stay there until she felt ready to leave. Then he added with gleaming eyes:

"Miss Farley, maybe in the meantime you could brew a Strengthening Potion. I know we haven't made practice in the Lab yet, but yesterday you did so well in your test that I don't think you'll face any problems trying by yourself."

Blushing slightly, Katerina began to work.

* * *

When she went away from Slughorn's office, the Sun had already set. She walked towards the Entrance Hall, but after a corner she almost bumped into Louis. He seemed to be waiting for her, because he looked at her rather impatiently.

"Go to the Library tonight at nine. Bring a jewel, a ring, or a necklace – something that belongs to you and that you can always carry with you," he quickly whispered, before walking past her without adding anything else.

When she reached the Entrance Hall, she released a sigh. Louis had been cryptic, and she didn't dare to hope he had find a solution for her little problem with the light – but she was just happy to think that in the next thirteen hours she wouldn't have to worry about it too much.

She didn't see her housemates until dinner. When she sat at the Ravenclaw table, she discovered that everyone already knew about the duel and was absolutely outraged by Louis' behavior.

"He must have told you something really horrible. You are usually so quiet and reserved," said Matilda.

"He deserved it! Louis Henry is in my Potions and Charms classes. He is an arrogant snob – he and his little gang always bother us while we are working," complained a sixth-year girl, Sunday Davis.

"Once he hit me with the same curse he used on you. It was a nightmare. We were outside, by the lake," remembered Stanley Ichabod with a grimace.

"Right. But the Bat-Bogey Hex you then cast on him was the best I've ever seen," added Sunday with gleaming eyes. Stanley laughed.

"Anyway, don't worry. The lessons you lost today were the most boring lessons ever," said Abigail to Katerina. She smiled.

"Well, I spent all day brewing Cure for Boils and Strengthening Potion. I know what you mean when you say _'boring'_," she joked. She heard Hayley Watson hold her breath.

"_You didn't_! Strengthening Potion? But we only saw the theory!", uttered the girl with a tinge of envy.

"Oh dear, someone here is going to be invited to the next party of the Slug Club," Abigail sniggered. Katerina stared at her and then made a face. She didn't need to meet the most influent people in school, now that she was supposed to stay hidden. She briefly wondered if Slughorn would be happy to have a vampire in his club; for some reason she doubted it. During the next Potions lesson she would have to blow up a cauldron. Or maybe two, for good measure.


End file.
